Radio control device



Aug. 7, 19 P. SCHWARZHAUPT RADIO CONTROL DEVICE m z l P V A a L w.

Invntr 7 Paul Schwarzhaupt y (be/6a; Hi5 Attorney Patented Aug. 7, 19341,969,528. namo con-moi. DEVICE Paul Schwarzhaupt Scotia, N. Y.,assignor to General Electric Company, a corporation of New YorkApplication April 25, 1933, Serial No. 667,851

4 Claims. (c1; 192-4) I My invention relates to radio control devicesand more particularly to an arrangement for locking the movable elementof a radio control device sequentially to the adjustment thereof.

In radio-apparatus, including receivers and transmitters, as used onaircraft and in other applications where the apparatus is subject tovibration, a tendency exists for the apparatus to work out ofadjustment. This is particularly true of variable capacitors andvariometers used for tuning radio'receivers and transmitters. It

is desirable to have a means which not only will lock such apparatus inposition, but which is simple to operate so that the apparatus may bequickly adjusted and locked into position.

It is, therefore, an object of my invention to provide a simple,economical and readily operable arrangement in connection with the radiocontrol device which, after adjustment of the control device, willsequentially lock it into position. A a

The novel features. which I believe to be characteristic of my inventionare set forth with particularity in the appended claims. My inventionitself, however, both as to its organization and method of operation,together with further objects and advantages thereof, will beunderstoodbest by reference to the following description taken inconnection with the accompanying drawing in which-Fig. 1 shows a simpleembodiment of my'invention, and Fig. 2 shows a preferred embodiment ofmy invention.

Referring to Fig. 1 of the drawing, I have illustrated therein a shaft1.5of a radio control device which may be invariable capacitor, avariometer or. some other device such as a variable resistor. A dial 2is mounted upon theshaft 1 to provide an indication of the angularadjustment of the movable element ofthe radio control device. A knob.3at one extremity .101 the shaft 1 servesas a convenient means foradjusting the angular position of the shaft. For the sake of cleamess, Ihave shown a brake drum 4 mounted on the. shaft 1 between the indicatingdial 2 and the knob 3, although it is i to be understood that it may bemounted at any point-on the shaft 1 and that it is generally preferableto. mount it behind the indicating dial The brake drum 4 is providedwith a brake strap 5,the extremities of which ,are

. fastened to the member 6. The member 7 may be a portion of theframework of-the variable radio control device or aportion I of thechassis of the radio receiver. A spring 8 is located between the members6 and 7 so as normally to exert a tension upon the extremities of thebrake strap 5. A lever 9 pivoted at 10 is arranged so that one extremityof the lever is beneath the member 6 and the other extremity of thelever extends to the front of the radio apparatus so as to be inproximity-to the knob 3.

In the operation of radio apparatus in places where there isconsiderable mechanical vibration, as for instance in aircraft, itis-desirable quickly to adjust the control devices of the equipment andto lock them sequentially in position so as to maintain the adjustment.In the arrangement shown in Fig. 1, the action of the r spring 8 is suchas constantly to apply a brake to the, shaft l to prevent rotationthereof. In order to adjust the radio control device, the operatorpresses upon the lever 9, thereby relieving the tension upon theextremities of the brake band 5 and then adjusts the radio controldevice by means of the knob 3. Upon completion of the adjustment, theoperator releases the lever 9 which immediately and sequentially to theadjustment locks the control shaft 1 in position so as to maintain theadjustment of the radio control device.

-Referring toFig. 2, I have shown therein a preferred embodiment of myinvention as applied, for example, to a variable capacitor comprisingthe stator 11 and a rotor 12. The rotor 12 is provided with a hollowshaft 13 uponwhich are mounted the indicating dial 14 and. the brakedrum 15. The brake drum 15 is pro-,

1 vided with a brake strap or band-16 which is fastened to one arm ofthe bell crank. 1'7. The bell crank 17 is pivoted in the member 18 whichmay be fastened to'the chassis of the radio ap- 'paratus. The member 18is provided with a -the rotor v1'2 of the variable capacitor. A rod 21provided with a knob 22 at one extremity is" mounted within the hollowshaft 13 so that one extremity of the rod 21 abuts against one .arm ofthe bell crank 1'7. The hollow shaft 13 is provided with a key 23 whichextends into a [slot 24 in the rod 21. The slot 24 is, of sumcientlength to permit longitudinal motion of therod21.' 1 The longitudinalmotion of the rod 2 1- actuates the bell crank 11 in a direction tooppose the action of the expansion spring 21 thereby releasing the brake16. Upon release of the vice may rotate the movable member of a devicewhich in the present example, is the rotor 12 of the variable capacitor.Upon adjustment of the rotor'12 the operator releases the-knob 22 andthe expansion spring 20 operates against the bell crank 17 to restorethe rod 21 to its original position and at the same time to apply thebrake 16 to the drum 15, thereby locking the rotor 12 in position. It isto be understood, however, that the braking means 15 and 16 may compriseany other suitable form of brake and that the use of a brake strap ismerely exemplary of the method of. solving the problem of preventingrotation of the variable member of a radio control device afteradjustment has taken place.

Fig. 1 therefore shows a simple and economical means for, preventing therotation of the movable member of aradio control device due to theaction of external mechanical vibrations.

The arrangement disclosed in Fig. 2 is preferable in that a singlecontrol member such ,as the shaft 21 and the knob 22 may be used toperform the operation of adjusting the movable member of the controldevice and preventing I the/normal braking action.

While I have shown and described my invention in connection with certainspecific embodiments, it will, of course, be understood that I donotwish to be limited thereto, since it is apparent that the principlesherein disclosed are susceptible of numerous other applications and thatmodifications may be made in the instrumentalities employed withoutdeparting from the spirit and scope'of my invention as set forth intheappended claims.

What I claim as new and desire to secure by Letters Batent in the UnitedStates is:

1. The combination of a radio tuning device having a rotatable shaft,means for adjusting said tuning device, a brake for said shaft, meansfor preventing the application of said brake during adjustment of saidtuning device, and means for applying said brake sequentially to saidadbrake 16,. the operator of the radio control dejustment, saidlatter-means including a biasing member normally actuating'said brake topremeans comprising a mechanical connection between said first two meanswhereby the second means is operated in response to an operation of saidfirst means distinctive from a tuning ad-.

justment operation.

2. The combination of a radio tuning device having a rotatable membermounted upon a shaft, means for adjusting the position of said rotatablemember, a brake drum attached to said shaft, a brake band for said drum,means whereby the application of said brake band during adiustment ofsaid tuning device is prevented by manipulation of said rotatablemember, and means for sequentially locking the rotatable member inposition after adjustment thereof, said means including a biasing membernormally acting upon said; brake band.

3. The combination of a radio control device having a rotatable shaft,means for adjusting said radio control-device, means for sequentiallylocking said shaft against rotation after adjustment, said meansincluding a brake drum fastened to said shaft, a brake strap mountedupon said drum, biasing means normally applying tension to theextremities of said brake strap, and means including a lever foropposing the action of said biasing means during the adjustment of saidradio control device.

4. The combination of a radio control device tached to said shaft, abrake for said drum, and,

biasing means normally applying said brake to said brake drum. F

PAUL

